MSI GeForce - Recent Questions, Troubleshooting & Support

It sounds like the frequency referred to is the monitor's frequency. If it's an LCD monitor, the frequency is usually 60Hz. If you are using a VGA cable, it's guessing the frequency and has guessed wrong. The other possibility is that the Railroad Tycoon game sets the screen resolution and frequency to something your monitor is not capable of displaying. It sees a nice graphics card and shoots the settings to the top of the range. If you can change the settings before playing the game, you might get it to work.

Check Nvidia's website.